Workaround for glibc 2.2.9x and later "a+" bug that does not seek to EOF for

files fopen()ed with that mode.

acinclude.m4

@@ -1455,6 +1455,45 @@ int main(void) {
   fi
 ])
 
+AC_DEFUN([PHP_BROKEN_GLIBC_FOPEN_APPEND],[
+  AC_MSG_CHECKING([for broken libc stdio])
+  AC_TRY_RUN([
+#include <stdio.h>
+int main(int argc, char *argv[])
+{
+  FILE *fp;
+  long position;
+  char *filename = "/tmp/phpglibccheck";
+  
+  fp = fopen(filename, "w");
+  if (fp == NULL) {
+	  perror("fopen");
+	  exit(2);
+  }
+  fputs("foobar", fp);
+  fclose(fp);
+
+  fp = fopen(filename, "a+");
+  position = ftell(fp);
+  fclose(fp);
+  unlink(filename);
+  if (position == 0)
+	return 1;
+  return 0;
+}
+],
+[have_broken_glibc_fopen_append=no],
+[have_broken_glibc_fopen_append=yes ])
+
+  if test "$have_broken_glibc_fopen_append" = "yes"; then
+	AC_MSG_RESULT(yes)
+	AC_DEFINE(HAVE_BROKEN_GLIBC_FOPEN_APPEND,1, [Define if your glibc borks on fopen with mode a+])
+  else
+	AC_MSG_RESULT(no)
+  fi
+])
+
+
 AC_DEFUN([PHP_FOPENCOOKIE],[
 	AC_CHECK_FUNC(fopencookie, [ have_glibc_fopencookie=yes ])
 

configure.in

@@ -382,6 +382,7 @@ sys/ipc.h \
 ])
 
 PHP_FOPENCOOKIE
+PHP_BROKEN_GLIBC_FOPEN_APPEND
 
 dnl Checks for typedefs, structures, and compiler characteristics.
 dnl -------------------------------------------------------------------------

main/streams.c

@@ -1317,6 +1317,12 @@ PHPAPI php_stream *_php_stream_fopen_from_file(FILE *file, const char *mode STRE
 	
 	stream = php_stream_alloc_rel(&php_stream_stdio_ops, self, 0, mode);
 
+#ifdef HAVE_BROKEN_GLIBC_FOPEN_APPEND
+	if (strchr(mode, 'a')) {
+		fseek(file, 0, SEEK_END);
+	}
+#endif
+	
 	if (stream) {
 		if (self->is_pipe) {
 			stream->flags |= PHP_STREAM_FLAG_NO_SEEK;
@@ -2417,7 +2423,7 @@ PHPAPI php_stream *_php_stream_open_wrapper_ex(char *path, char *mode, int optio
 		}
 	}
 
-	if (stream && stream->ops->seek && (stream->flags & PHP_STREAM_FLAG_NO_SEEK) == 0 && strchr(mode, 'a')) {
+	if (stream && stream->ops->seek && (stream->flags & PHP_STREAM_FLAG_NO_SEEK) == 0 && strchr(mode, 'a') && stream->position == 0) {
 		off_t newpos = 0;
 
 		/* if opened for append, we need to revise our idea of the initial file position */